Telephonic transmitter



(ModeL) 2 Sheets-Sheet 1.

G. E. SHAW.

TELBPHONIG TRANSMITTER.

Patented Jan. 2, 1883.

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(ModeL) 2 Sheets-Sheet G. E. SHAW TE'LEPHONIG TRANSMITTER.

No. 270,136. Patented Jan.2,1'883.

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Mo Maw UNITED STATES-PATENT OFFICE.

- GEORGE E. SHAW, F GHIGAGO,ILLINOIS, ASSIGNOR TO THE SHAW TELE- PHONIO COMPANY or AMERICA, or SAME PLACE.

TELEPHONIC TRANSMITTER.

SPEGIFIOATION forming part of Letters Patent No. 270,136, dated January 2, 1883.

Application filed February 23, 1881 (Model.)

To all whom it may concern Be it known that I, GEORGEEDWIN SHAW,

of Chicago, in Cook county, of the State of Illinois, have invented ncwand useful Improvementsin 'l-elephonicTransmitters, of which the following is a specification, reference being bad to the drawings tiled andvthe letters and figuresmarked thereon, forming a part of the said specification, in which IO Figure 1 is an elevation; Fig. 2, a vertical cross-section, showing the bar-magnet suspended; Fig.3, a similar section, showing the bar-magnet supported; Fig. 4, a similar section, showing the position of an adjustable at mature; Fig. 5, a detail showing the platina point attached to the diaphragm, also the compress J; Fig. 6, a detail showing the position of the radial magnets G G.

My improvements pertain to the class of tele- 2o phonic instruments known as microphones,

having a diaphragm in connection with a platina point and a block ot'carhon, which con stitnte the electrodes' My invention consists in supporting one of the electrodes of a microphone in contact with the other electrode by the attraction or repulsion existing between permanent magnets. This I do by freely pivoting and suspending at the upper end a bar-magnet or a bar of any material, the free end of which ismade susceptible of magnetic influence by attaching thereto a magnet or magneticmaterial; or the magnet or bar may be supported by resting its lower end on a base for the purpose of hold- 5 ing said magnet or bar in front of the electrode attachedto a diaphragm, so that an electrode attached to the magnet or bar will, when in proper position, make contact with the electrode attached to the diaphragm. The mag- 0 net or bar is held in working position by the attraction or repulsion exerted on its freeend by permanent magnets or magnetic material placed radially about its free end; or the mag net may he held in its working position and 4 5 contact of the electrodes regulated by the at traction of said magnet for an armature of steel or iron secured to the frame and adjusted by a suitable screw. It is obvious that if the free end of Yhebar is terminated with an armature only there must be magnets to hold it in adjustment, while if the bar is terminated with a magnet or is itself a magnet it may be retained in its working position by the attraction or repulsion of other magnets or pieces of magnetic material placed radially about its free end.

In the drawings,A indicates the diaphragm; B, the platina point or one of the electrodes; 0, a front plate or door of a microphone; D, the oscillating magnet or bar; E and E, brack- 6o ets; E, a supporting-base for the magnet or bar; E, a staple or guide around the topot' the magnet; E, a bridge or bracket which supports one of the magnets or pieces of magnetic material; F, the block of carbon or the 6 electrode attacheilto the magnet or bar; G, an armature attached to the frame; G G, adjustable permanent magnets or bars of magnetic material; H, a battcry-wire; J, a pressure bar or spring; K, a wire or its equivalent attached to one of the electrodes; at b, disks or cleats forattaching the electrode to the diaphragm, also serving to hold the wire K' or its equivalentto said electrode; d, a rubber gasket or band; (2, clamps or binders for fastening the diaphragm to the frame or door of microphone; a and 8, north and south poles of the permanent magnets.

The magnet or bar D, as shown in Fig. 1, is held in suspension at the upper end by two points or trunnions from a projecting bracket, E, which is attached to the frame 0, so as to allow the lower end of said magnet or bar D to swing free; or it maybe supported at the lower end, as shown at E, Fig. 3, allowing the upper end to oscillate freely in a wire staple, E, the magnetor bar D in either of the devices shown heing held in its working posi' tion, so as to bring the electrode F, attached to the magnet or bar D, into contact with the 0 electrode B, attached to the diaphragm A, by the attraction or repulsion of the magnets or pieces of magnetic material G G, which are placed radially about the free end of said magnet or bar D. The magnet or bar D is provided with a block ofcarbon, F, or its equivalent, which is attached to the magnet or bar D in any suitable manner, and is placed upon the magnetor bar-D opposite the platina point B, which is attached to the diaphragm A, the zoo magnets G G being so arranged that one of them is held in its position by passing itof contact of the electrodes is regulated.

through a hole in the frame 0, the other magnet being supported in its position by a bracket or bridge, E. The electric battery current (battery not shown) is conducted by the wire H to the carbon F, to which wire H is attached in any suitable manner. The magnet or bar I), whether in the suspended or supported form, is at the free end adjusted in its working position by means of the attraction or repulsion of the poles of the magnets or pieces of magnetic material GG acting on its free end. These radial magnets are adjustable by movingthem to or from the free end of the suspended or supported magnet or bar D, and thus the force Attached to the frame 0 is a spring or compress, J, the under side ofthe free end of which is provided with a pad of any suitable nonconducting material, and rests upon the (liaphragm Afor the purpose of holding the wire K or its equivalent tirmly upon the diapl'rra gm A. Said wire Kis attached to the electrode 13, and passes under the pad J and on the diaphragm A, and from thence is conducted to the ordinaryinduction-coil. (CoilnotshOWtL). Said compress J also acts as a damper to tone the vibrations of the diaphragm. The compress J is secured to the frame (J by a suitable screw, whichit is obvious serves to adjust its pressure upon the diaphragm. Said diaphragm, when made of mica, is pierced at or near its center to receive the platina point or electrode 13, which is secured to it (the diaphragm) by the two metal disks or cleats a I). Said disks or cleats also serve to hold the wire K or its equivalent to the electrode or platina point B. The periphery of said diaphragm A is surrounded by a rubber gasket or band or any suitable non-conducting material, and is held upon the frame 0 by suitable clamps, e, or in any manner that will hold it firmly to the frame 0, the frame 0 being provided with an aperture, 0, for the purpose of conveying sounds to the diaphragm A. The microphone thus described is intended to be used in a closed circuit.

Having thus described the microphone and its construction, what I claim as new and as" my invention, and desire to secure by Letters Patent, is

1. In a microphone, a diaphragm carrying one electrode, in combination with a bar susceptible of magnetic induction, freely supported, and carrying another electrode, and two other bars acting magnetically upon the supported bar, so as to attract or repel the same in opposite directions, substantially as described. 7 r

2. In a microphone, a bar-magnet carrying an electrode, and pivoted at one end so as to allow the other end to freely rnove, in combination with a diaphragm carrying another electrode, and adjustable radial magnets arranged,as shown, to act on the tree end of said bar-magnet, so as to attract or repel the same in opposite directions, for the purposes described, and substantially as set forth.

3. In a microphone, a diaphragm of mica, pierced to receive an electrode, in combination with such electrode. a bar-magnet carrying another electrode, and pivoted at one end soas to allow the other end to freely move, and adjustable radial magnets acting on the free end of said bar-magnet, so as to attract or repel the same in opposite directions, substantially as described, and for the purposes set forth.

GEORGE EDWIN SHAW. Witnesses:

Geo. H. EDWARDS,

JNo. J. CHASE. 

